Guess how long it takes to form a clear first impression that is unlikely to be revised? 1/10 of a second. That’s all is takes for someone to judge you based on your face.

Allowing more time for impressions doesn’t change that judgment. In a series of experiments, judgments were remarkably consistent across subjects – people tend to judge others similarly. The two traits most quickly judged are attractiveness (of course) and trustworthiness.

Why is trustworthiness so important?

Because we evolved to avoid people who wish to harm (or kill) us.

“The authors suggest, based on evolutionary psychology, that an accelerated and accurate ability to judge trustworthiness in others may have evolved as an important survival mechanism.”

Prior research has suggested that we make a first impression within ten seconds or so, primarily based on our appearance. Most people interpret that as a reference to how good looking a person is. Dating advice often emphasizes that sexual attraction occurs within this time frame between strangers. But that totally misses the character assessment rapidly taking place.

Harvard Business School professor Amy Cuddy‘s most recent work focuses on first impressions. According to Cuddy, first impressions – whether between potential mates or professional colleagues – are all about answering just two questions:

Can I trust this person?

Can I respect this person?

In order to make that critical judgment quickly, we look for signs of warmth and competence. Together, those signs account for 80-90% of a first impression.

Warmth is the quality that makes another person feel understood. That’s a prerequisite to establishing trust, because it gives us clues about the other person’s intentions towards us. Competence is the ability to carry out those intentions.

In contrast, a firm handshake and aggressive greeting conveys dominance, which is associated with manipulative, self-serving motives. Dominant behavior makes other people feel threatened.

“From an evolutionary perspective, [warmth] is more crucial to our survival to know whether a person deserves our trust…If someone you’re trying to influence doesn’t trust you, you’re not going to get very far; in fact, you might even elicit suspicion because you come across as manipulative. A warm, trustworthy person who is also strong elicits admiration, but only after you’ve established trust does your strength become a gift rather than a threat.”

Trustworthiness vs. Dominance

These two traits are opposites – you cannot be perceived as both simultaneously. (Trash any unfortunate nonsense you’ve picked up from pickup sites suggesting that acting dominant will attract women.)

Furthermore, the perception of trustworthiness is linked to pitch and glide, things we can modify by choice. Dominance is linked to immutable physical traits, such as the length of one’s vocal tract.

Of course, these snap judgments may not be accurate. But the research shows that they are consistent and resistant to revision. Both sexes value trustworthiness and are repelled by dominance.

Facial features

We assess trustworthiness via moveable, expressive features such as the eyes and mouth. In contrast, we perceive dominance via rigid, immobile features such as the width of the jaw, or distance between the eyes. (For more info, check out this post on female attraction cues.)

Since you’ve only got 1/10 of a second, it’s important to back up (or alter) the first impression you make with strategies for building warmth and trust.

1. Let the other person speak first.

According to Amy Cuddy:

“Let the other person speak first or have the floor first. You can do this by simply asking them a question. I think people make the mistake, especially in business settings, of thinking that everything is negotiation. They think, “I better get the floor first so that I can be in charge of what happens.” The problem with this is that you don’t make the other person feel warmth toward you.”

2. Invest time in making small talk.

“You can also establish trust by collecting information about the other person’s interests — get them to share things about themselves. Just making small talk helps enormously.”

3. Sustain eye contact.

Research shows that people who make eye contact are perceived as more intelligent. Eye contact also suggests integrity – even as children we know to avoid eye contact when we’re guilty.

4. Use appropriate facial expressions.

Smiles have been found to play a role in forming impressions. A large grin tends to convey naivete – we see it as goofy. But a subtle smile with a small upturn of the mouth conveys both intelligence and friendliness.

These strategies come naturally to some, but they are skills that can also be learned. A lot of what we perceive as “creepy” behavior in social situations is actually a failure to use these strategies. Lack of curiosity about the other person, unnatural or stilted small talk, lack of eye contact, and facial expressions that don’t inspire trust.

What about dominance required for leadership?

I wondered about people who are dominant by definition, e.g. CEOs, politicians, etc. While many are perceived as untrustworthy, that’s not always the case. Aren’t there times when dominance and competence are the right combination? Here’s what Cuddy has to say:

“In general I really think people make the mistake of over-weighting the importance of expressing strength and competence, at the expense of expressing warmth and trustworthiness. I think this is a mistake.

How can you possibly be a good leader if the people who are supposed to be following you don’t feel that you understand them? How is it possible? No one is going to listen if they don’t trust you. Why would they? Why should they?

Trust opens them up to what you have to say. It opens them up to your strength and confidence. Trust is the conduit through which ideas travel.